The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1887-01-12
A BIG TELESCOPE.
THE LARGEST IN THE WORLD
IS IN CALIFORNIA.
What the Colossal Instrument OF the
Lick Observatory is Expected
to Reveal Moon
Sixty Miles Away.

The approaching completion of the
colossal telescope of the Lick Observa-
tory, in California, lends interest to the
question: How powerful will this tele-
scopic giant be2" The Lick telescope
is to be by far the largest refractor in the
world. Those who have seen the huge
telescope of the Naval Observatory in
Washington will be interested to know
that the California giant will survey the
sky with an eye tea inches broader than
that of tie great star gazer at the capi-
tai. The pupil of the human eye would
have to be enlarged to diameter OF three
feet in order to collect as much light as
will fall upon this wonderful OBJ ject glass
of the Lick telescope. As the average
diameter of the pupil of the eye is about
one. fifth of an inch, it follows that man
whose eye was large enough to equal the
great telescope in light-grasping power
would be about 1000 feet tall. The
statue of Liberty would serve him for q
cigar lighter, If hung up where he could
conveniently reach it. -.
So much for the power of the Lick
wonder to gather starlight. The magni-
flying power is another thing, though it
depends directly upon the amount of
light that the telescope can grasp. An
ordinary opera glass magnifes two and
half or, at the most, three diameters.
Let any one recall how effective even so
low magnifying power as that is when
applied to persons and objects upon q
distant stage, and then he will at once
perceive the signifcan"e of the statement
that the smallest astronomical telescope
will bear magnifyiug power of two or
three hundred diameters. The relation
between the magnifying power of an op-
tical instrument, reckoned by diameters.
and the apparent distance Of the object
looked at is very simple. If an opera
glass magnifies three diameters, it shows
objects as they would appear at only one
third of their real distance from the eye.
So telescope magnifylng 200 diameters
would show man mile away as if he
were standing within about twentysix
feet of the observer. But only tele copes
constructed for astronomical purposes
will stand magnifylng powers like that,
and, moreover, in consequence of the
impurity and unsteadiness of the air near
the earth, and the lack of illumination of
terrestrial objects, the image in such a
case would be more or less blurred and
indistinct. The same power, 200 diane
ters, applied to the moon brings it with
in an apparent distance of about 1900
miles, and shows clearly the extinct era
tiers, empty sea bottoms, and ragged
mountain ranges of our satellite.
Now as to the magnifying power Of
the Lick telescope. It has been found
that when the most skiful opticians have
done their best in making telescope
object glass, it will bear, under favorable
conditions, and for certain purposes, a
msgnifying power of one hundred diam
eters for each inch of it's own diameter.
The object glass of the Lick telescope is
thirty-six inches across; therefore it
should be able to stand a power of $500
dismeters, but only under the finest con-
ditions. Such a power applied to the
moon would bring it, when nearest to
the earth, within an apparent distance of
little above sixty miles. Under the
most favorable circumstances, an object
upon the moon as large as St. Patrick's
Cathedral could probably be seen with
such power as q white speck. But or
dinarily a power only one-half or one
third as great as that could be used with
advantage So, as far as the ability of
the great telescope to reveal them is con-
cerned, the moon might be swarming
with inhabitants who would still remain
out of the reach of our eyes. But If
cities or other great artificial works ex-
listed there they would doubtless be
clearly distinguishable, and should, IN
fact, long ago have been perceived with
telescopes much smaller than. the Colos-
sus of Mount Hamilton. The new tele-
scope can, then, only be expected to
add little more evidence to the proof
that the moon is an extinct planet,
world of desolation, where all the great
creative forces have ceased to operate
and nature seems to have reached the
end of her tether.
But with the planets the case is differ
ent. Recent observations have shown
the existence of enigmatical features on
Mars. upon which the Lick telescope may
be able to throw much light. Its great
size is not the only advantage it will
possess. Being placed upon a mountain
top it will be above the denser and more
impure portion of the atmosphere. which
is source of perpetual and unconquer-
able difficulty to astronomers whose
telescopes are situated at lower levels.
Then the atmosphere O. the Pacific coast
appears to be exceedingly clear and
steady, 50 that an enormous advantage
is gained in that respect. Here in the
East, and in Engllnd and most parts CT
Europe, an astronomer is lucky if ne finds
q dozen or even half do en- nights in a
year when the atmospheric conditions
are good enough to permit the u>e of the
highest powers of his telescope. Oh erva-
tions taken on Mount Hami ton, the site
OF the Lick telescope, show that as many
as two hundred and fifty nights in year
may be expected to furnish such oppor-
tunities for first. class work. With such
ad dsantages the great telescope should
largely increase our knowledge Of the
huge planet Jupiter, and of the changes
going on there which clearly indicate
that it is an orb that is now in the act
of transformation from sun into a
world.
With respect to the fixed stars, OF
other suns than ours, the Lick glass will
prove its superiority on account OF its
enormous light graeping, or, as it is
called, 81 ace -penetr. ting power. This
same property, together with the excep-
tionaIly excellent atmospheric conditions
amid which it is situated, will enable 1t
to reveal new wonders among the